This disclosure relates to polyester compositions, in particular crosslinked polyester compositions, their methods of manufacture and uses.
Polyesters, copolyesters, and their blends with other thermoplastics have a number of advantageous properties, including high mechanical strength and good processability, which make them useful in a wide variety of applications. Nonetheless, there remains a continuing need in the art for methods for adjusting specific properties of polyesters, such as their thermal resistance, chemical resistance, flame retardance, and the like.
One method of altering polyester properties is by crosslinking, for example by irradiation of the polyester. Irradiation crosslinking has limitations due to cost and availability. In addition, irradiation is affected by, or could interfere with, additives such as dyes, pigments, and antioxidants. Chemical crosslinking using a crosslinking agent such as a multifunctional acrylate or multifunctional epoxy resin in the presence of an initiator such as a peroxide and a tertiary amine accelerator has also been used. However, these processes are heat sensitive and difficult to control, which can lead to inconsistent results or unwanted side effects during processing of the polyester, for example extrusion.
There accordingly remains a need in the art for methods for crosslinking polyesters and the crosslinked polyesters formed thereby. It would be advantageous if such methods were predictable, and readily adaptable to large scale manufacture. It would further be advantageous if the methods were controllable, such that adjustment of the crosslinking conditions allowed tailoring of the properties of the crosslinked polyester.